Commit omission

lib/acts_as_taggable_on/taggable/core.rb

@@ -53,7 +53,7 @@ def #{tag_type}_list=(new_tags)
                 if Rails.version.to_f < 6.0
                   set_attribute_was('#{tag_type}_list', #{tag_type}_list)
                 else
-                  d_mutations_from_database.change_to_attribute('#{tag_type}_list')
+                  duplicated_mutations_from_database.change_to_attribute('#{tag_type}_list')
                 end
                 write_attribute("#{tag_type}_list", parsed_new_list)
               end
@@ -69,6 +69,17 @@ def all_#{tags_type}_list
             def dirtify_tag_list(tagging)
               attribute_will_change! tagging.context.singularize+"_list"
             end
+              
+            def duplicated_mutations_from_database
+            unless defined?(@mutations_from_database)
+              @mutations_from_database = nil
+            end
+            @mutations_from_database ||= if defined?(@attributes)
+              ActiveModel::AttributeMutationTracker.new(@attributes)
+            else
+              NullMutationTracker.instance
+            end
+          end
           RUBY
         end
       end